One customer asked why he cannot update Dolphin XP005L firmware since January. He tried many times to update V3.2.2 firmware successfully but it continued to require update.
Here is the Solution:
Switch to developer mode and update firmware, and then switch back to user mode and update again.
How to switch to developer mode?
Go to
System>> ? >> Yes
*Without the guidance of technical engineers, you can’t switch this mode privately, otherwise you need to bear the consequences
Done! Hope this could help!
Skype: xhorsevvdi.com
Whatsapp: https://wa.me/8613983756354
Whatsapp: 
Skype: